Draft regulation for furnaces



u ,15,1944. R. G. wYLD 2,355,897

DRAFT REGULATION FOR FURNACES FiledApril e, 1942 IINVENT'OR Ffiglka]! G. WyZd I 1M. $.44 72%: zri m ATTORNEYS.

( furnace-comprising an insulated jacket ing and supportinga fire chamber llfcomprising 1 an upper section 12 and a lower section I3. The

Patented Aug. 15, 1944 DRAF REGULATION FOR FURNACES Reginald GfWyld, Dayton, Ohio, assignor to Chrysler Corporation, ration of Delaware Application April 6,

Detroit, Mich., a corpo- 1942,Serial No. 437,787

3 Claims; gor. 158-28) My present invention relates to fuel burning appliances of the fuelvaporizing type, the cornbustion of the fuel being accomplished in a burner comprising a receptacle having perforations Referring to=Figsl 1, 2, and 3,- the invention is disclosed as being-associated witha warm air In enclos- P'g ln ord er to rnaintaina stable upper and lower sections are separated from each other by a partition I4 as disclosed in my copending application, Serial No. 437,786, filed concurrently herewith. A burner [5 of the fuel vatherethrough for admitting combustion support 5 porizing type having combustion supportingair ing air into vapors formed by the vaporization openings ,HS in the side wall thereof and includof liquid, fuel by the heat/ 0f previously consumed ing a top combustion ring I! having a centralized fuel. The present invention is illustrated in conflame opening l8 therethrough is supported by nection with a warm air furnace, butitisjtobe the partition M in such fashion that the only pp ted that it is of utility, in any heating 10 communication between the upper and lower secappliance, such as boilers,- jwater heaters,;space .tions of the fire chamber is through the perforaheaters and the like. T r ,i tions l6 and the flame opening 18. The flame The primary object of thepresent inventionis may be inspected through an inspection door to maintain a stable flame in a fuelj vaporizing and access to the burner may be had 'through a burner.' It is common knowledge that fuel va- 15 removable cover plate 2|. The flame may'lbe porizing burners operating under natural draft caused to wipe the Walls of the upper sectionv 12 are subject to a number of influences lwhich'upbefore passing through the flue connector 23 by set the character of the flame, possibly causing means of a flame spreader 22 suspended in the warping, cracking, or burning through of portions upper section. Fuel is admitted to the interior of the burner, excessive andflame chokingfor- 20. of. the burner receptacle through an inlet'ftube mation of soot in carbon deposits, reduc'tionof 25 having connection toa fuel metering device combustion efficiency, or other harmfulefiects. 26 monuted on the cover plate 2| and which is With the present invention the fuelis "consumed adapted to admit metered quantities of fuel. A at a constant rate and ma stable manner at high pilot ring 27 may be mounted in the burner reefliciency by the establishment of flow of com 25 =ceptacle for supporting low flame combustion. A bustion supporting air in constant quantities and forced draft blower 30 is mounted ,on the cover at constant pressures regardless of fluctuations [plate 2! and is preferably driven by an electric inthe stackpressures or other factors commonly motor 3| having connection through cable 32 to causing difficulties; i r i a control device 33 adapted to coordinate the ac- A further object of the present 'inventionis toff tion of the blower with the action of the meterprovide means for preventing the'formation of ing device so that the blower operates when high hot spots in the walls or bottom of a vaporflame fuel quantity is being admitted to the burnizing burner so as to eliminate failures due to er and ceasesto operate when pilot flame fuel warping, cracking, or the like. 7 j v i quantity is being admitted to the burner.

These and other objects and advantages of the, Details of the fuel metering device 26, the blowpresent invention will be more readily apparent er control device 33, and the burner l5 in themfrom an inspection of the accompanyingspecifiselves are not essential to the present invention cation and drawing wherein-like numerals refer and further disclosures thereof are not thought to'like parts throughout. 4 r I necessary, there being many such devices known In the "drawing; f i I 1 to those skilled in the art. The fire chamber ll Fig. 1' discloses a warm air furnace having the is illustrated as being built in the form of a drum present invention associated' therewith; J but it should be obvious to those skilled in the art Fig. 2 is a partial front view of-a portion of thatothe'r shapes may be utilized if desired. The the furnace disclosed in Fig. 1; U a l burner. is illustrated as being cylindrical in shape Fig. S'is an enlarged sectional view of a portion since such a shape is common and adapts itself of the furnace disclosed in Fig. 1; to a drum shaped flre chamber, but it should be Fig. 4 is a schematic representation of a modiapparent to those skilled in the art that other fication of the invention; and r a v H r shapes and types of fuel vaporizing burners hav- Fig. dis a schematic representation of afuring perforations for admitting air therethrough thermodification; l may be used. Further details of the furnace construction may be ascertained from the cope'nding applications of 'Allen P. Livar, f led concur- ;rently herewith and identified as Serial Nos.

.437 ,7 99 and 437,801, respectively;

flame when the "desired quantity of air counterbalance Weight 45.

tion, of the flue above the extension 52 exceeds a desired amount, the flapper plate 44 will open is provided witha large opening Lneath the bottom of the burner so that theair forced into the perforations I6 first fiows'acro'ss" the bottom of the pot before approaching the perforations. i

burner is on high flame operation I prefer supplying a forced draft blower capable of supplying more air than necessary to support efiicient combustion against a static pressure higher than that desired. I have found that a positive static pressure maintained in the lower section I3 of approximately .05 inch W. C. is a desirabl pressure for forcing air through the perforations I6, and I prefer to have the blower capable of forcing a greater quantity of air than necessary and capable of operating against a static pressure of .07, .08, or more, inch W. C. In order to the static pressure at a lower point, I-provide' an opening through the blower mounting plate 36 which communicates with the section I13 so some portion of the burner so that heat may be carried away from the burner or the walls of the lower section to maintain a safe temperature.

as to permit the escape of air from the space I3."

The size of the opening 35 is carefully selected in relation to the sizes and numbers of the'per forations I6 and the maximum capacity of the blower 30 so as to maintain a constant flow of a H at the desired pressure through the perforations I6.

' e quantity of air admitted into the burner I5 may vary if the stack pressure varies. It is well-known that thesuction established by various chimneys varies considerably over a wide range and even in a single chimney the static pressure may vary when the wind changes, down drafts occur, the chimney is cold or hot; or other factors.

dooratmosphere for carrying away the products of combustion and I associate with this flue pi pe section of the flue pipe 40, upon which is mounted a cap 43. A flapper plate 44 is pivotally mounted in'theopen end of the cap and is provided with may be turned to adjust the moment arm of the As soon as the sueto admit air from the room and thus maintain the suetionbelow the extension 42 at a constant desired negative pressure. 7

I have determined that a desirable total pressure for the air admitted to the pot is approxi- 'mately .08 inch W. C. Accordingly, I prefer to adjust the pressure regulator II-tomaintain approximately .03 inch W. C. negative static pressure in the upper section I2 and the interior of the burner I5. The resulting effective pressure-dif ferent'ial between the interior and exterior of the burner pot is thus. .08 W. C. thereby causing Ithe quantity of air admitted to the fuel to b maintained constantly at that quantity whichv can pass through the pre'forations at OB-"inch" W. C. A 7

In order to prevent excessive heating ofthe bottom of the burner I5 and to assure uniform In the modification disclosed in F g. 4, instead of theopening '35 I disclose a pressure regulating.

7 Accordingly, I connect the flue connector 23 to a flue pipe leading to the-outa counterbalance weight 45 carried by an ad ,justing screw 46 having a knurledknob 41 which Q distribution of air around the burner, I preferably device 60, comprising 'a hinged 'flapper' plate (if i6 A further function of the pressure regulating l5i sureforcing air through the perforations.

In the modification disclosed in Fig. 5, the

opening -I5I in the secondbaffie I50 corresponding to bafile 50 of Fig.1 is located at the back of the space so that the flow of air through the opening I5I toward the draft regulating device 60 passes around the walls and bottom of the burner.- Furthermoratherewould be less tend- 'ency for stagnation of hot air -between the burner andthe closely adjacent rear wall of the heating drum in this modificatio It'is to be appreciated that the draft regulating device 60 in each of the modifications disclosed in Figs. 4 and 5 constitutes an opening for the escape". of excess air. The flapper plate 6| fmay be omitted in each case, if desired, and the size of the opening carefully selected in order that the opening may correspond to the opening 35 of the first modification. Having illustrated and described several preferred embodiments 'of the" present invention, it should be apparent to those skilled in the art that the same permits of various modifications in arrangement and detail. All such modifications as .come within the scope of the following claims are to be considered a part of my invention.

I claim:

1. A heating appliance comprising a fire chamber, a partition dividing said fire' chamber into upper and lower sections, a fuel vaporizing burner having perforations to admit combustion supportingair into the fuel vaporized by the heat of previously burned fuel and a top combustion'ring having a flame opening therethrough, said combustion ring being associated with said partition so that the sole communication between said .up-

per and lower sections is through said perforations andsaid flame opening, means to force air into said lower section in greater quantity than required for efficient combustion of the fuel, said means being capable of creating a static pressure in excess of the desired static pressure at the perforations of the burner, means to permit the escape of the excess air-from said lower section whereby to maintain the flow ofthe desired quantity of air through said perforations at a desired static pressure lower than the pressure at which the air could be forced into the lower section by said air forcing means, and a draft regulatorv in communication with said upper section and atmosphere for maintaining a constant negative pressure in the interior, of said burner.

2. A heating appliance comprising a fire cham- -ber,:a partition dividing said fire chamber into 1 upper and lowerfsections, a fuel vaporizing burner havingperforations to admit combustion supporting air and a top having a flame opening therethrough, said top being associated with said partition so that the sole communication between said upper and lower sections is through said perforations and said flame opening, means to force air into said lower section, a second partition dividing said lower section into an air admission space and a burner containing space, said second partition having an opening therethrough so arranged as to direct the air flowing therethrough against portions of said burner likely to become overheated, and a pressure regulating device communicating directly with said burner containing space for maintaining a substantially constant positive static pressure in the later forcing air through the perforations of the burner.

3. A heating appliance comprising a fire chamber, a partition dividing said fire chamber into upper and lower sections, a fuel vaporizing burner having perforations to admit combustion supporting air and a top having a flame opening therethrough, said top being associated with said partition so that the sole communication between said upper and lower sections is through said perforations and said flame opening, means to force air into said lower section, a second partition dividing said lower section into an air admission space and a burner containing space, said second partition having an opening therethrough so arranged as to direct the air flowing c therethrough against portions of said burner likely to become overheated, and a pressure regulating device associated with said burner containing space for maintaining a substantially constant positive static pressure forcing air through the perforations of the burner, the position of said burner being in the path of air flow intermediate said second partition and said pressure regulating device to thereby cause the air to flow in a stream surrounding said burner while travelling from said second partition opening to said pressure regulating device.

REGINALD G. WYLD 

